Leveling apparatus and method



May 2, 1950 L. THEIMER LEVELING APPARATUS AND METHOD 2 Sheets-Sheet 1 Filed July 9, 1945 INVENTOR. Leo The/mew BY MLLW A T TORNEY May 1950 Filed July 9, 1945 l... THEIMER LEVELING APPARATUS AND METHOD 2 Sheets-Sheet 2 MLW ATTORNEY Patented May 2, 1950 UNITED STATES PATENT ormcr:

LEVELING APPARATUS AND METHOD Leo Theimer, New York, N. Y.

Application July 9, lciaseriai No. $03597 6 Claims. (01. 51-165) q H (Granted under the act of March 3', 1883, as

amended April 30, 1928; 370 O. G. 757) The present invention relates to an apparatus and method for leveling an object with reference to a level liquid surface, and more specifically the invention relates to an electrical arrangement for measuring the distance from an index point on an object to a level liquid reference surface.

In the construction of large and heavy precision machines of the type having a rotary turret for carrying a tool such as a polishing tool, it is customary to design the machine so that it can be mounted upon a supporting deck with the axis of the turret disposed vertically so that the tool can revolve with the turret while rotating upon its own axis to perform the polishing. The work to be machined is customarily disposed above the rotary tool turret and is rigidly supported independently of the machine upon standards mounted on the supporting deck.

In performing precision machining operations it is essential that thepiece of work shall be accurately and precisely positioned with respect to the machine tool. For example, in using a precision machine such as a Sellers machine for polishing the lower bearing surface of the rotary carriage for a large-caliber multiple-gun mount it is necessary that the Sellers machine and carriage bearing surface be accurately positioned relative to each other so that the upper polishing surface of the machine tool in operation de scribes a path coincident with the lower bearing surface of the carriage to be polished. .;.To insure accurate positioning of the work and machine with respect to each other it is' found convenientv to establish a liquid body having a level free surface and to level the machine by reference to the liquid surface with subsequent leveling of the Work by reference either to the liquid surface or previously leveled machine. A suitable arrangement for leveling the machine is to establish the liquidbody in an annulus surrounding the rotary tool turret and to establish an index point on the rotary tool turret so that a micrometer measurement of the distance from the index point to the liquid surface can be made. By making such measurements in several different positions of rotation of the rotary tool turret it is possible to detect any tilt in the machine and to make adjustments to bring the machine into level position.

The work to be polished can then be leveled with reference to the machine by taking micrometer measurements of distance fromthe index point on the rotary tool turret .to the lower hearing surface to be machined. Taking such measurements in different positions of rotation of the 2 rotary tool turret makes it possible to detect any tilt in the work and adjustments can be made to bring the work into level position. If desired, th y work can be leveled by reference to the liquid sur face instead of reference to the leveled machine by making micrometer measurements of the distance from the lower bearing surface of the work to the liquid level at different points.

Because it is necessary that the leveling of the work and machine be accomplished with precision, the micrometer measurements must be made with precision. Experience has shown that when such measurements are made manually and when contact between the end of the micrometer and the surface of the liquid is estimated by eye sum cient errors of manipulation and estimation are introduced tocause perceptible inaccuracies in the leveling operation. The present invention overcomes these objections by providing means for making the necessary micrometer measurements automatically and eliminating human error. In measuring the distance from the index point of the rotary tool turret to the liquid reference surface, preferably an electric motor is arranged to move the micrometer relative to the index point on the rotary tool turret, and to bring one end of the micrometer into contact with theliquid surface, an additional electrical system being provided automatically to stop the electric motor and arrest the micrometer upon'contact of the end of the micrometer with theliquid surface. V An object of this invention is to provide an anparatus and method for levelingan object with respect to a level reference surface formed by aliquid body. p f Another object is to provide an apparatusan'd method for positioning a pair of objects relative to each other by leveling the objects with respect to a level reference surface formed by liquid body. Another object is to provide an apparatus for automatically measuring the distance from an index point on an object to a level reference surface formed by a liquid body.

Another object is to provide a micrometer for measuring the distance fromanindex point on an object to a reference surface formed by a liquid body together with electrical means for moving the micrometer relative'to the index point and into contact with the liquid surface and additional electrical means for arresting the micrometer upon contact with the liquid surface. [Further objects and advantages of this invention, a'swell' asits construction. arrangement and operation, will be apparent from the following ported by means of brackets It and adjustment screws 55 upon a supporting deck It. Adjustment of screws l permits leveling of machine I I. Mounted on the top of rotary tool turret I3 is a tool support I! that is secured thereto in any-suitable manner as, for example, by welding. A bracket I8 servestoaid in. anchoring support I? in .place. Tool support l?! is provided. with an. oifset. arm I9 adapted to support a rotary tool 29 having an upper surface 2i adapted to perform a polishing operation. In. operation turret I3 rotates and. carries toolifi. along. with it while at the same. time tool 2.0. is rotating upon its own axis. Tool therefore simultaneously revolves about theturret axis androtates about its own axis to perform thepolishing operation.

Disposed abovetool 29. is a piece, of work 22 comprising, a cylindrical carriage portion 23 for amultipleegun. mount. 2 !.v Carriage 23 is. provided. with a. lower bearing surface 25. to, be polishedjby means of tool 29. Workpiece 22. is supported. in place by means of. check blocks 26 thatarewelded theretov and secured in. any. suitable manner to brackets '21. Each bracket is supported bymeansof an.adjustment bo1t28-upcame-seating surface .29 of a vertically disposed standard 30.. Each standardfiil is supported upon a base plate 3I disposed on. deck Ilfiand issecured in-place by means ofbrackets32. Adjustment of bolts L28..is made to level. workpiece '22.

Disposed about machinebase. I2 is anannular trough 33that is secured to machine base I2 .by means of supporting. blocks.34 .preierably-madeof electrically-insulating material. Disposed withintrough 3.3.is .aliquid body 35. having a free-level suriace36. Liquid 35..is.composed of any suitable electrically conductive substance. Depending into the liquid body-35 is an electrode 31 supported by. trough-3.3.

Secured to the side wall of rotary. tool. turret I3 in any suitable manner. isaibracket 38'having an upper horizontal arm '39 and a lower horizontal. army 49,. Adapted. for vertical reciprocation with respect to. bracket 39'isa micrometer 4 I havingathreadedportion 42 adapted for. threading through .an idlergear iILsupportediorrotationon bracket arm. 39. Powerfor rotating idler gear 43 issupplied byv an electric. motor 44' mounted by means. oi. a base 45 upon bracket 38 and having a driving gear A6 thatsmeshes with idler gear 43. .Qperation. of motor 44 causes rot'ationof driving gear. 46 and. idler gear 43.. which by means of threads. 42 causes. vertical. movement of micrometer 4'].

Lower. bracket arm iil is providedwith a guide plate. 4.1 insulated therefrom by an insulating block 48. Guide plate 4.1. serves tov guide micrometer 41 inits vertical movement toward and away 7 from the liquid surface 36. An index finger 49. is, mountedv on. bracket arm 4!) and adapted to register. with calibration marks 50 on micrometer 4|. Microm'eter M is preferably deail) signed so that the lower portion thereof which is adjacent and below guide plate 41 is electrically conductive and adapted to form part of an electric circuit to be hereinafter described. The upper portion of micrometer 4| above guide plate ii is. insulated from the lower conductive portion as seen at 50.

The electrical system for moving micrometer 4| is illustrated in Fig. 3. A circuit is provided including the electric motor 44 that has a binding post EI and is-connected by means of a conductor 52 through a reversing switch 55 and conductor 55 to-a power terminal 53. The other power terminal es is connected by a conductor 51 to a terminal 58 of an armature 59 pivoted as indicated at 53 and held against contact 6| by means of a spring, 62., Contact BI is connected by means of a conductor 6.8 through reversing switch 56 and conductor 64 to the other binding post 65 of motor 5.4. .A.knife switchtii is provided across lines63 and El. With terminals 53. and. 54 'connect'edto a suitable source or power (not shown), reversing switch 5 5 can. be closed to cause operation of motor i l; rotation ofdrive gear ifi and rotation of idler gear G3 to effect movement oflmicromet'er ti. Reversing of switch {it causes opposite r0- tation of motor i l and gears 4t and 4.3. to'cause reversed. movement of micrometer 4"I'.

Ase'cond circuit is provided including electrode 3'! connectedby means ofja conductorG-Iinseries wit'na lamp es and one terminal 69 oi-a suitable source oi power (not shown). The otherpower terminal Iii is connected by means of--a conductor. ii to winding. 12 of a relay 13;provid;ed'with;

a core it and a pole piece E5. The endof windm cz isconnected "by means of a conductor 16 to a binding post TI on guide 4?; The circuit'is completed by the lower end of micrometer ,4I and liquidbod'y 35 both ;of which are electrically conductive as hereinbefore described. The; lower tip of micrometer. 41' constitutes a movable electrical contact which can be moved/toward. or away fromgl'iquidsm'face 3B which constitutes a second electric'alcontacti. With terminals 692 and is connected to a suitable source of. power (not shown).., whenever micrometer iI isymove'd' by motor e linto contact with liquid surface 36'; the circuit is closed. andyrelay '13 is energized to attract armatur 59". away. from cOntact 61'. to open the circuit including motor 4'4 wherebymot'or it. is stoppedan'd micrometer II is arrested.

In. operation, machine I I is mounted upon deck i6 and adjustedyby means of screws I5 into approximately level position. Workpiecef22" is. thenmoun'ted by means of. cheek blocks 26,:bracketsiii'andistandards.ti iupondeck16.. By adjustment ofscrews 2B workpiece 22 is brought intoapproximately level position.

Finai'accurate leveling of. machine. I Land workpiece 22is accomplishedin the followingmanner; Annular trough 33 is mounted'in positionabout machine base I2 by means of supportingbrackets 34 and filled to. a suitable depth with liquid'35; Since liquid 3Shas. a free surface 225 the latter is level regardless of. any tilting that is'p resent in trough 33.; Bracket 33. is then mounted upon rotary tooljturret i3 and motor 44; drive gear; idler gear 43, micrometer 4i and guide plate 4! are. assembledas shown in. Fig. 1" with-the lower end o'f'micrometer. il withdrawn from l'iquid'surface 36. Electrical connections are made-to the various parts as indicatedin Fig. 3' with terminals 53. and. 54' connectedjto. any suitable source; of. power (not shown). Terminals... 6.9 and Til are connected'to a suitable source of power (not shown). Reversing switch 56 and knife switch 66 are in open-circuit position.

A measurement of the distance from index point 49 to liquid surface 36 is now made by c1osing switch 56 so that motor 44 causes rotation of drive gear 46 and idler gear 43 to move micrometer 4| downwardly. Upon contact of the lower end of micrometer 4! with liquid surface 36 the circuit including conductive liquid body 35 and electrode 3'! is closed to energize relay l3 and cause withdrawal of armature 59 away from contact 6! whereby the circuit including motor 44 is opened and micrometer 4| is arrested. Lamp 68 is lighted under these conditions to indicate that micrometer 4! has been arrested and a reading should be made. A reading of the calibration mark that is in registration with index 49 is taken to indicate the distance between the index point and liquid level 36.

Switch 56 is next thrown into a reverse position and knife switch 66 closed to close the cir cult when relay armature 59 is in open position whereby motor 44 reverses and by means of drive gear 43 and idler gear 43 causes upward movement of micrometer 4i. Reversing switch 55 is opened to arrest micrometer 4! in a position wherein the lower extremity thereof is slightly withdrawn from liquid surface 36. Separation of micrometer 4| from liquid surface 36 causes relay is to become de-energized with the result that armature 59 returns under the influence of spring 62 into engagement with contact 6 I. Knife switch 66 is thereupon opened and the electrical circuits are conditioned for making another measurement.

Rotary tool turret i3 can be rotated into several other positions and readings of the distance from index 49 to liquid surface 36 made for each position. Variations in the readings indicate tilting in machine I l with respect to level liquid reference surface 36 and an adjustment of screws l can be made to correct such tilt and bring the machine into level position.

Workpiece 22 can be leveled with respect to previously leveled machine H by measuring the distance between index 49 on machine H and lower bearing surface 25 of workpiece 22 that is to be polished. Measurement can be made by the following procedure. With the electrical circuit arranged as described above in connection with the operation of leveling machine ll, switch 56 is closed to operate motor 44 and cause upward movement of micrometer 4|. Upon contact of the upper end of micrometer 4| with bear ng surface 25, reversing switch 56 is opened to arrest micrometer 4| and a reading made of the calibration mark 50 that registers with index 49. Switch 56 is then reversed to withdraw micrometer 4! a suitable distance from bearing surface 25 and switch 56 is then opened to arrest micrometer 4| and condition the system for another measurement. Rotary tool turret'l3 is turned into several different positions and measurements in each position made. Variations in the measurements of the different positions indicate tilting of workpiece 22 and adjustment of screws 28 is made to bring the workpiece into level position. "1

In leveling workpiece 22 as described contact between the upper end of micrometer 4| and bearing surface 25 is estimated by eye. However, if desired, an automatic electrical arrangement analogous to that provided with liquid body 35 can be used so that the measurement is fully automatic.

6 Also if desired workpiece 22 can be leveled by direct reference to liquid surface 36 instead of referring to previously leveled machine ll.

Modifications and changes can be made in this invention without departing from the spirit and,

scope thereof as set forth in the appended claims.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

What is claimed is:

1. The method of leveling a pair of objects each having an index surface that comprises establishing a liquid body having a free surface forming a level reference surface, disposing the first of said index surfaces approximately parallel to said reference surface, establishing an index point in said first index surface, rotating said first index surface about an axis perpendicular thereto, measuring the distances between said index point and said reference surface at three or more positions of rotation of said index point, adjusting the object having said first index surface until said distances measure substantially the same whereby said first index surface is made parallel to said reference surface, disposing the second of said index surfaces approximately parallel to said first index surface, rotating said first index surface about an axis perpendicular thereto, measuring the distances between said index point and said second index surface at three or more points of rotation of said index point, and adjusting the object having the second index surface until said distances measure substantially the same whereby said second index surface is made parallel to said first index surface.

2. In combination, a machine having a portion mounted for rotation about a vertical axis and means for leveling said machine comprising adjustment screws for supporting said machine upon a supporting surface and also comprising a container having a body of liquid having a free surface forming a level reference plane, an index on said machine, measuring means mounted for vertical movement to measure the distance from said index to said reference surface, an electric motor for causing downward movement of said measuring means to bring the lower end thereof into contact with said reference surface, an electrical contact on the lower end of said measuring means, an electrical contact included in said liquid reference plane, and electrical means interconnecting said contacts and motor whereby closing of said contacts will stop said motor and arrest said measuring means.

3. An electrical system for measuring the distance from an object to the surface of an electrically conducting liquid body that forms a reference surface by means of a. scale adapted to move relative to the object to bring one end of the scale in contact with the liquid surface, said electrical system comprising a first electrical contact on the end of the scale for movement toward said reference surface, a circuit including a motor for moving said scale toward said reference surface which forms a second electrical contact, an armature switch in series with said motor and adapted to be in closed-circuit position when said contacts are separated, a second circuit including said contacts, and a relay in series with said contacts and positioned adjacent said armature switch whereby closing of said contacts causes said relay to become energized and open said 7: immature switch. to stop said. motor and. arrest SMd:SC.3JE-.

4. The method of leveling anobjecthaving an index. surface which. comprises providing a liquid body having. a free. surface forming. a level reference surface, disposing the index surface approximately. parallel to said referencesurfacaestablishing an index. point on said index surface, rotating, saidiindex surface-about an, axis. perpendicular. thereto-measuring. the distances between. saidindex point and said reference. surface. at. three or more positions of rotation. of, said index point andi adjusting the, object. until. said distances. are equal so. that said. index. suriace is, parallel.- ta said reference surfaca.

5. lncombinatioma. machine having a portion mounted. for. rotation. about. an axis. means for tipping; said Portion, a. container, having, therein electrically conducting liquid having. a free surface. extendingaround said axis, an. index associated: with. said, rotatable: portion, and. electrical. me ns: for measuring the, distances, between: said. suriacaand said index at a plurality of positions. taken; by said index. upon. the. rotation of said rotatable portion, said. electrical, meansv including a. circuit including at. least a portion, of said liquid, whereby said. rotatable. portion may be tipped. to make. those. distances equal. which in turn assuressaid. axis being in line. with. g avity andany surface of said rotatable portion perpenldicular to said axis being horizontal.

6. In combination, a machine having a portion mounted for rotation about an axis, means for tipping said portion, a container having therein. electrically conducting liquid having a freesinzface at a plurality of points aroundsaid'laxisan index associated with said rotatable. portion,. and electrical. means for measuring the distances. between said surfaces and said index at a plurality of positions taken by said. index upon the. rota? tion of said rotatable portion, said. electrical;

means including a circuit including. at. least aportion of said liquid whereby saidrotatable pottion may be tipped to make those distancesequsl'i which in turn assuressaid axisbeing inlinerwithi gravity and any surface. of said rotatable POI! tion perpendicular to said axis being horizontal; LEO THEIMEBc.

REFERENCES CITED.

Thes'f'ollowing references are of record-in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,294,831 Carson Sept. 1;,1942 2,385,247 Yeomans Sept. 18;.19 t5 

